ABSTRACT

Vi
(visual) is a display oriented interactive text editor.
When using
vi
the screen of your terminal acts as a window into the file which you
are editing. Changes which you make to the file are reflected
in what you see.

Using
vi
you can insert new text any place in the file quite easily.
Most of the commands to
vi
move the cursor around in the file.
There are commands to move the cursor
forward and backward in units of characters, words,
sentences and paragraphs.
A small set of operators, like
d
for delete and
c
for change, are combined with the motion commands to form operations
such as delete word or change paragraph, in a simple and natural way.
This regularity and the mnemonic assignment of commands to keys makes the
editor command set easy to remember and to use.

Vi
will work on a large number of display terminals,
and new terminals are easily driven after editing a terminal description file.
While it is advantageous to have an intelligent terminal which can locally
insert and delete lines and characters from the display, the editor will
function quite well on dumb terminals over slow phone lines.
The editor makes allowance for the low bandwidth in these situations
and uses smaller window sizes and
different display updating algorithms to make best use of the
limited speed available.

It is also possible to use the command set of
vi
on hardcopy terminals, storage tubes and glass tty's using a one line
editing window; thus
vi's
command set is available on all terminals.
The full command set of the more traditional, line
oriented editor
ex
is available within
vi;
it is quite simple to switch between the two modes of editing.

To preserve the practical use of this document
as a vi introduction
more than twenty years after its original creation,
annotations have been made for this edition
to reflect changes in the environment or in the editor itselves.

Note: The text is often presented in eight sections.
This is obviously result of a mistake
and was thus corrected for this edition.
When the subsection on Word Abbreviations was introduced for
4.0BSD in between the existing subsections
on Macros and Abbreviations, it was labeled with
a .NH macro instead of a .NH 2 one.
But in troff -ms, .NH means
the same as .NH 1, start a numbered top level section.
So Word Abbreviations became the seventh section in print,
and Nitty-gritty details the eighth one,
breaking all existing references to the seventh section.